Animal life first appeared on the earth about 400 million years ago. Through the passing millennia, thousands of animal species have come and gone. Until recently, this process was gradual, the result of changes in climate, in habitat, or in the genes of the animals themselves. (46. But the tremendous expansion of modern civilization now threatens to upset this natural balance, putting unprecedented pressure on the survival of our wildlife. )
This imbalance can be traced to many causes. Most arise in the greed and poor planning of man himself. (47. With each increase in man's population the wilderness areas where the animals live get smaller. The use of pesticides to control injurious insects also harms wild birds and animals.) Water pollution kills fish in our rivers, lakes, and oceans. Hunters have almost exterminated many of the larger animals like the bighorn sheep and the grizzly bear. And farmers destroy smaller animals like the prairie dog and the coyote. As a result of this unrelenting pressure, our wildlife is disappearing at the rate of one species or subspecies per year.
(48. Of all the continents. the most drastic reduction in wildlife has occurred in North America. where the transition from a rural to a highly industrialized society has been most rapid.) Among the victims are birds, mammals, and fish. We will never again see the passenger pigeon or the eastern elk. They have been wiped out. Of, many other species, only a few representatives still survive in the wild. The U.S. Department of the Interior has put no fewer than 109 species on the endangered species list. (An endangered species is one with poor prospects for survival and in need of protection.) This list includes everything from the timber wolf to the whooping crane. Even the bald eagle, our national symbol, is threatened.
Animals that kill other game for food are called predators. The predators include the wolf, mountain lion, fox, bobcat, and bear. (49. Attack against these animals began with the arrival of the first European settlers. who wished to protect their livestock. Eventually, a reward was offered to hunters for every predator that was killed.) This reward is called a bounty. Ironically, the Federal government is the chief funder of predator-control programs.
The settlers also brought with them their Old World fears and superstitions concerning predators. Whether preying on livestock or not, predators were shot on sight. This attitude continues to this day for coyotes, eagles, foxes, mountain lions, and bobcats, and is largely responsible for placing the eastern timber wolf, grizzly bear, and bald eagle on the endangered species list.
Yet every animal, including the predator, has its place in nature's grand design. Predators help maintain the health of their prey species by eliminating the diseased, young, old, and injured. Predators like the mountain lion and the wolf help to keep the deer herds healthy. (50 Their kill also provides food for scavengers that feed on carrion. Occasional loss of livestock must be weighed against the good these animals do in maintaining the balance of nature.)
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